A fortune! (about $100 )
a hand knit scarf is one of kind, custom made clothing.. it should be priced as such.. if you try to 'compete' price wise with off shore machine made (in mass quantiy) stuff, it won't cover the cost of the yarn. (unless, you too buy pallets of cones of yarn!)
feel bad about charging that much? have them make the check out to your favorite charity...